Technical Field
The present disclosure relates to a display device included in equipment for implementing virtual reality and adjusting the brightness of the display device.
Description of the Related Art
Display devices provide a variety of information graphically on a screen and are the core technology of the era of information and communications. Accordingly, thinner and lighter display devices are being developed. Recently, different types of display devices for different applications have been developed. As one of such applications, there is an on-going research into a head mounted display (HMD).
As its name implies, a HMD is worn on or attached to a viewer's head and is frequently used as equipment for implementing virtual reality and/or augmented reality, sometimes in conjunction with 3D display technology. The virtual reality is the technology that establishes a simulation environment by using computer techniques and enables a viewer to experience a similar environment of the real world. Namely, a HMD allows a viewer to feel a virtual image as if it was real by providing vivid images, video, voice, etc. As a HMD is worn on a viewer's head, it also has lenses that allow the viewer to see things that are nearby. Referring to the HMD shown in FIG. 1 according to a related art, the HMD may include a display device 10, a control device 200, lenses 300, a holder 400, and a cover 500.
The display device 10 may include a light and thin display device such as a liquid-crystal display (LCD) device, an organic light-emitting display (OLED) device, etc. The display device 10 is a type of a virtual reality display. The control device 200 may include a variety of sensors and processors and recognize a user's motions by using sensor technology and wireless technology to reflect it on a screen. Such technologies help improve the reality of contents displayed on the display device. Fish-eye lenses are frequently used as the lenses 300. A fish-eye lens is an ultra wide-angle lens that has an angle of view of 180 degrees or higher and gives a spherical view of the world thereby improving reality. The holder 400 secures the HMD to a viewer's head. The cover 500 is a component that covers the display device 10, the control device 200, the lens 300 and the holder 400 are coupled with one another.
A HMD shows images close to a viewer's eyes and thus the viewer can be deeply immersed into the displayed environment. This is why the HMD is developed for implementing virtual reality. Accordingly, HMDs have been applied to military training, medical service, aerospace development, as well as augmented reality industrial and educational purposes, virtual reality (VR) experience devices, monitors for wearable PCs, theme parks, movies, and gaming display devices, etc.
In virtual reality devices such as HMDs, images are displayed right in front of the eyes, and thus such display devices need to address certain technical issues. Here, the present inventors recognized that such display devices for virtual reality need to achieve a certain level of high resolution display capabilities for improving the user's immersion experience, need to resolve form factor issues (e.g., wearable comfort, weight reduction, etc.), and the like.